This is how you are to eat it: You must be fully dressed for travel, with your sandals on your feet and your staff in your hand. You are to eat in haste; it is the LORD’s Passover. — Exodus 12:11

Israel ate the Passover in haste, loins girded, ready to move. That's the pilgrim posture — bags packed, because this world isn't home. Peter picks this up: gird up the loins of your mind and hope fully on the grace to be revealed. You're not settling down here. Christ your Passover has been sacrificed, and you're heading to the promised rest.